A Comparison Between Corona and DBD Plasma Actuators for Separation Control on an Airfoil

In this work, an experimental study on the effectiveness of the multi-tip geometry for plasma actuators is presented for a separation control problem. The multi-tip geometry consists in a periodical series of triangular tips on the active electrode edge. Both DC corona and AC Dielectric Barrier Discharge (DBD) actuators are considered and their performances are compared. The plasma actuators are installed on the leading edge of a NACA 0015 airfoil and tested at high angles of attack in the wind tunnel for freestream velocities in the range 5 – 20 m/s. The flow control mechanisms are briefly discussed. Force measurements are performed by means of an aerodynamic balance and the force coefficients are derived. Electrical measurements are also performed, to quantify the consumed power. The actuators effectiveness is evaluated through some suitable performance parameters. In general, a properly chosen multi-tip geometry is found to be more performing than traditional straight edge configurations, both for coronas and DBDs. Furthermore, corona actuators give comparable aerodynamic performance with respect to DBDs, but they require an order of magnitude lower power.